1. Field of the Invention
The present invention relates to an endoscope apparatus mainly used in the industrial field, which is inserted into a space, such as the inner space of a pipe, to inspect it.
2. Description of the Related Art
In general, an industrial endoscope has a slender insertion section, which is inserted into a to-be-inspected space, such as the inside of a pipe. In most cases, the proximal end of the insertion section is coupled to a hand-side operation section. A head portion is provided at the distal end of the insertion section. The head portion incorporates an observation optical system for observation, illumination optical system, etc. A bendable portion is provided behind the head portion. The directable section can be bent in vertical and horizontal directions. The tips of a plurality, e.g. 4, of bending wires are secured to the bendable portion. The proximal end of each bending wire is extended rearward (toward the hand-side). The end of the extended portion of each wire is coupled to a bending mechanism provided at the hand-side operation section.
Further, an operation knob is provided at the hand-side operation section. The operation knob is used to drive the bending mechanism and bend the bendable portion. When the operation knob is rotated, the bending mechanism is driven. When the bending mechanism is driven, the bending wires are pulled, thereby bending the bendable portion in the direction corresponding to the operation direction of the operation knob.
Also, an inner channel (treatment instrument insertion channel), through which a treatment instrument, such as forceps, is inserted, is formed in the endoscope. The front-side opening of the inner channel is situated in the head portion of the insertion section. Furthermore, the forceps port (proximal end opening) of the inner channel is situated in the operation section.
In accordance with recent bending mechanisms, which are motorized, bending may be performed using the manual operation knob, or switched to motorized bending means. For example, U.S. Pat. No. 5,373,317 discloses a bending-operation input means equipped with a joystick for generating a signal corresponding to an inclination angle.